Merge pull request #6622 from kinke/fixEffectiveAlignment

[stable] Fix std.experimental.allocator.common.effectiveAlignment()
dlang · Jul 3, 2018 · 320d4f8 · 320d4f8
2 parents c14e879 + cce5771
commit 320d4f8
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Showing 2 changed files with 6 additions and 3 deletions.
diff --git a/std/experimental/allocator/building_blocks/bitmapped_block.d b/std/experimental/allocator/building_blocks/bitmapped_block.d
@@ -99,7 +99,7 @@ private mixin template BitmappedBlockImpl(bool isShared, bool multiBlock)
         auto leadingUlongs = blocks.divideRoundUp(64);
         import std.algorithm.comparison : min;
         immutable initialAlignment = min(parentAlignment,
-            1U << trailingZeros(leadingUlongs * 8));
+            1U << min(31U, trailingZeros(leadingUlongs * 8)));
         auto maxSlack = alignment <= initialAlignment
             ? 0
             : alignment - initialAlignment;

diff --git a/std/experimental/allocator/common.d b/std/experimental/allocator/common.d
@@ -287,16 +287,19 @@ Returns the effective alignment of `ptr`, i.e. the largest power of two that is
 a divisor of `ptr`.
 */
 @nogc nothrow pure
-package uint effectiveAlignment(void* ptr)
+package size_t effectiveAlignment(void* ptr)
 {
-    return 1U << trailingZeros(cast(size_t) ptr);
+    return (cast(size_t) 1) << trailingZeros(cast(size_t) ptr);
 }
 
 @nogc nothrow pure
 @system unittest
 {
     int x;
     assert(effectiveAlignment(&x) >= int.alignof);
+
+    const max = (cast(size_t) 1) << (size_t.sizeof * 8 - 1);
+    assert(effectiveAlignment(cast(void*) max) == max);
 }
 
 /*